Noonan syndrome and moyamoya

We report a patient with Noonan syndrome and asymptomatic cardiac disease (supravalvular aortic stenosis and pulmonary valvular stenosis) who had frequent transient ischemic attacks. Bilateral moyamoya was evident; in addition, he manifested activated protein C resistance and was heterozygous for the factor V Leiden mutation. Anticoagulation abolished his episodes and, despite extensive cerebrovascular disease, he has no permanent neurologic deficits. The association between Noonan syndrome and moyamoya has not previously been described. Disruption of vascular development in prenatal life may have resulted in both cardiac and cerebrovascular disease in this child.